it's the cup shape type of stamped metal nut with a washer-like flange that's a touch larger than the hole, not really a speed nut ... haven't seen them in any catalog, but a standard nut with washer would do

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics